Triphenylamine/Tetracyanobutadiene‐Based π‐Conjugated Push–Pull Molecules End‐Capped with Arene Platforms: Synthesis, Photophysics, and Photovoltaic Response

Abstract

p-Conjugated push-pull molecules based on triphenylamine and1 ,1,4,4-tetracyanobuta-1,3-diene (TCBD) have been functionalized with different terminal arene units. In solution, these highly TCBD-twisted systemss howeda strong internal charge transfer band in the visible spectrum and no detectable photoluminescence (PL). Photophysical and theoretical investigations revealed very short singlet excited state deactivation time of % 10 ps resulting from significant conformational changes of the TCBD-arene moiety upon photoexcitation, opening ap athway for non-radiative decay.T he PL was recovered in vacuum-processed films or when the moleculesw ere dispersed in aP MMA matrix leading to as ignificant increase of the excited state deactivation time. As shown by cyclic voltammetry,t hese molecules can act as electron donors compared to C 60 .H ence, vacuum-processedp lanar heterojunction organic solar cells were fabricated leading to am aximum power conversion efficiency of ca. 1.9 %w hich decreases with the increaseo ft he arene size.

Excited state dynamics and exciton diffusion in triphenylamine/dicyanovinyl push–pull small molecule for organic optoelectronics

“…2 b). Similar behavior (known as solid state luminescence enhancement) has been previously reported 31 , 32 and assigned to a conical intersection (CI) between excited and ground states of the molecule in the liquid phase. To support such scenario for the TPA-T-DCV-Ph-F molecule, we performed time-dependent density functional theory (TDDFT).…”

Understanding how Lewis acids dope organic semiconductors: a “complex” story

“…We also checked the inuence of the OT range separation parameter u on the resulting optimized structures. 30 Using a RSH functional oen comes along with a non-empirical tuning of u. In fact, for each specic N-electron system, an optimal value of u can be found by enforcing the exchange-correlation functional to obey the DFT version of Koopman's theorem by aligning the negative energy of the HOMO with the gas-phase vertical IP.…”

Synthesis and emission properties of 1,1,4,4-tetracyanobutadienes derived from ynamides bearing fluorophores

“…16 However, some examples of luminescent TCBDs in solution or in the solid state have recently been reported. [17][18][19][20][21][22][23][24][25] Nevertheless, quantum yields were often very low at room temperature and hardly higher than 1%, with the exception of the paper of Jayamurugan et al 24 where the authors claimed quantum yields up to 4.3% at room temperature in acetonitrile. In parallel of these studies, we also studied TCBDs bearing triphenylamine and fluorenyl units that showed quantum yields comprised between 2 and 6% in rigid media at room temperature.…”